Android/iOS/Web: If you're still on the hunt for a solid Astrid alternative (or just a really good to-do app to try), GQueues may be the perfect choice. It's packed with useful features, integrates nicely with Gmail/Google Apps, supports iOS and Android phones and tablets, looks great on the web, and more.

GQueues has all of the features you would expect from a solid to-do app. Recurring items, tagging and categories to keep your lists organized and separate, subtasks and dependencies, drag-and-drop reordering, and public task sharing so you can delegate items to other people, whether they're using GQueues or not. GQueues also features "Smart Queues," or pre-defined categories that help you see just overdue items, things you have to do today, or just important items.